Track2Agenda: 03-dns-nagios-exercises.txt

NAGIOS MONITORING
-----------------

On Master server

1. Go to Nagios working directory

        $ cd /usr/local/etc/nagios
        
2. Copy Nagios sample files

        To do this, make sure you are in Nagios working directory from the first step
        There are Nagios's sample files in the directory, which we need to copy them 
    as working copies. The easiest is to become temporarily root, and rename
        the files:

        $ sudo -s

        You can then copy the commands below:

cp cgi.cfg-sample cgi.cfg
cp nagios.cfg-sample nagios.cfg
cp resource.cfg-sample resource.cfg
cp objects/commands.cfg-sample objects/commands.cfg
cp objects/contacts.cfg-sample objects/contacts.cfg
cp objects/localhost.cfg-sample objects/localhost.cfg
cp objects/templates.cfg-sample objects/templates.cfg
cp objects/timeperiods.cfg-sample objects/timeperiods.cfg

        # exit
        $
        
3. Create monitoring configuration files for DNS Servers 

        While are you still in Nagios working directory, create a new file for DNS servers monitoring
        
        Change the following below:
                xx:     your group number
                yy:     group number of your slave server
                MYTLD:  your zone name
        
        $ sudo vi objects/dns-servers.cfg
        
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### Define the host server

define host{
        use                     freebsd-server
        host_name               master
        alias                   master
        address                 10.10.xx.1
}

define host{
        use                     freebsd-server
        host_name               cache
        alias                   cache
        address                 10.10.xx.3
}

define host{
        use                     freebsd-server
        host_name               slave
        alias                   slave
        address                 10.10.yy.1
}

### Define the group

define hostgroup{
        hostgroup_name  dns-servers
        alias           DNS Servers
        members         cache,master,slave
}

### Define Services

define service {
        use                             generic-service         ; Name of service template to use
        hostgroup_name                  dns-servers
        service_description             PING
        check_command                   check_ping!100.0,20%!500.0,60%
}

define service {
        use                             generic-service         ; Name of service template to use
        hostgroup_name                  dns-servers
        service_description             Check DNS
        check_command                   check_dns!www.MYTLD
}

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4. Add check_dns service

        By default, Nagios doesn't configure check_dns service, we need to add line below into commands.cfg
        
        $ sudo vi objects/commands.cfg

        - Place this below the check_nt service check definition:

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define command{ 
        command_name    check_dns
        command_line    $USER1$/check_dns -s $HOSTADDRESS$ -H $ARG1$
}

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5. Enable DNS monitoring group in Nagios configuration files

        Now you have DNS Server monitoring files (dns-server.cfg) created. We need to enable on nagios.cfg file for monitoring
        
        $ sudo vi /usr/local/etc/nagios/nagios.cfg

        Look for the line "cfg_file=/usr/local/etc/nagios/objects/localhost.cfg" and add below content
        
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# Definition for DNS servers
cfg_file=/usr/local/etc/nagios/objects/dns-servers.cfg

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6. Enable Nagios service 

        To enable nagios service add the line below in /etc/rc.conf
        
        nagios_enable="YES"
        
        
7. Start Nagios service

        To start nagios service
        
        $ sudo service nagios start
        
        Nagios should be running right now without any error report.


8. Create Apache password authentication file for Nagios 

        Nagios required authentication via http to gain admin access to it web interface. 
        Let's create the password file
        
        $ sudo -s
        # htpasswd -c /usr/local/etc/apache22/nagios.auth nagiosadmin
        # exit
        $
        
        Set your desire password (perhaps, use the class password)
        
        Password file is now created
        
9. Create Nagios' Apache configuration for web interface access

        Go to Apache Includes directory 

        $ cd /usr/local/etc/apache22/Includes

        If there already is a nagios.conf file in the directory, we wil
        remove and rebuild it. Our new configuration is significantly different.
        To do this do:

        $ sudo rm nagios.conf
        
        Then edit the file:
        
        $ sudo vi nagios.conf
        
        Add the lines below into the file: 
        
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AddType application/x-httpd-php .php
AddType application/x-httpd-php-source .phps

ScriptAlias /nagios/cgi-bin/ /usr/local/www/nagios/cgi-bin/
Alias /nagios/ /usr/local/www/nagios/

<Directory "/usr/local/www/nagios/cgi-bin">
        Options ExecCGI
        AllowOverride None
        Order allow,deny
        Allow from all
        AuthName "Nagios Access"
        AuthType Basic
        Require valid-user
        AuthUserFile /usr/local/etc/apache22/nagios.auth
</Directory>

<Directory "/usr/local/www/nagios">
        AllowOverride None
        Order allow,deny
        Allow from all
        AuthName "Nagios Access"
        AuthType Basic
        Require valid-user
        AuthUserFile /usr/local/etc/apache22/nagios.auth
</Directory>

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10. Now, edit the main apache config.
        
        $ sudo vi /usr/local/etc/apache22/httpd.conf
        
        Find the line:

DirectoryIndex index.html
        
        And change it to:
        
DirectoryIndex index.html index.php


11. Enable and start Apache web service if required, by adding this
        to /etc/rc.conf

        $ sudo vi /etc/rc.conf

apache22_enable="YES"

        (Save file and exit)

        $ sudo service apache22 restart
        
12.     Access to Nagios web page via http://10.10.xxx.1/nagios/

        You will need to user "nagiosadmin" as the user and the password you 
        specified previously using the "htpasswd" command.

        Take a looking around the Nagios interface to see what is being 
        reported.